METHOD FOR ROTARY-PERCUSSION DRILLING OF WELLS AND MACHINE FOR ITS REALIZATION Russian patent published in 1994 - IPC

FIELD: mining. SUBSTANCE: method consists in supply of aerated fluid with aeration factor of 1-50 to percussion machine and its transformation into impact pulses acting on bottom hole. Percussion machine includes body with sleeve, striker separating body hollow into working chambers of forward and back strokes, drilling tool and system for distribution of energy carrier among working chambers. Distribution system has upper supplying-discharging and command channels of forward stroke chamber, and back stroke chamber is provided with controlled lower supplying-discharging valve installed in zone of interaction of drilling tool and striker which forms command channel together with sleeve. Lower supplying-discharging valve is made in form of bushing with inner bore and bead with circular discharging channel formed between inner surface of bead and drilling tool. Valve is installed in body for axial displacement and interaction with sleeve. EFFECT: higher efficiency. 5 cl, 2 dwg